Temperature (Global)

Global Temperature: NCAR/UCAR, NCDC, and NASA GISS Analysis: The current analysis uses surface air temperatures measurements from the following data sets: the unadjusted data of the Global Historical Climatology Network (Peterson and Vose, 1997 and 1998), United States Historical Climatology Network (USHCN) data, and SCAR (Scientific Committee on Antarctic Research) data from Antarctic stations. The basic analysis method is described by Hansen et al. (1999), with several modifications described by Hansen et al. (2001) also included. Modifications to the analysis since 2001 are described on the separate Updates to Analysis.

When assessing temperatures beyond the instrumental record, which only dates back into the 1,800's one must examine what is called paleo evidence. this evidence originates in many types of paleo records including but not limited to ice cores, ocean and lake sediments, fossilized pollen and insects, geologic and chemical isotope analysis and many more. The global temperature assessment is derived form multiple global analysis examining different types of data. It is the composite view and associated confidence levels, including uncertainties and the error range that produces the mean analysis. The confidence on the 'mean' is likely, most likely, or extremely likely to be the more accurate view as opposed to the outliers in the error potential. By collating multiple data sets the confidence interval can be increased based on the individual confidence intervals. It is this remaining confidence level that gives us a more reliable view of the best estimates of the mean temperature of Earth.

The National Academy of Sciences, National Research Council, Board on Atmospheric Science and Climate Present:

'Climate Change: Lines of Evidence - Is Earth Warming?'

The National Academy of Sciences, National Research Council, Board on Atmospheric Science and Climate Present:

Gerald Meehl - NCAR (National Center for Atmospheric Research)

Gerald "Jerry" Meehl is an NCAR senior scientist. His research includes connecting the solar cycle to subtle changes in weather and climate on Earth; examining the consequences of global warming, including heat waves, droughts, storms, and other weather extremes; regional climate change; and El Niño and other influences of the tropics on global climate.

Twice as many record-breaking high temperatures have been set compared to record lows across the U.S. in recent decades (seehttp://www.ucar.edu/news/releases/200...). For future climate, computer models show the ratio climbing to 20:1 by 2050 and 50:1 by 2100.

Day-to-day variability means we still get record cold days, but the record highs are far exceeding the lows.

NASA/GISS Analysis

Analysis Graphs and Plots

GISS Surface Temperature Analysis

Analysis Graphs and Plots

This page is updated each month by an automatic procedure. Additional figures based on the GISTEMP analysis which require manual effort to create are available from Columbia University webpages maintained by Dr. Makiko Sato; see page 1 and page 2.

Click on any graph to view an enlargement of the image. PDF documents require a special viewer such as the free Adobe Reader.

Global Annual Mean Surface Air Temperature Change

Line plot of global mean land-ocean temperature index, 1880 to present, with the base period 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. [This is an update of Fig. 1A in Hansen et al. (2006).]

Our traditional analysis using only meteorological station data is a line plot of global annual-mean surface air temperature change, with the base period 1951-1980, derived from the meteorological station network [This is an update of Figure 6(b) in Hansen et al. (2001).] Uncertainty bars (95% confidence limits) are shown for both the annual and five-year means, account only for incomplete spatial sampling of data.

Annual Land and Ocean Mean Temperature Change

Annual Mean Temperature Change for Three Latitude Bands

Annual and five-year running mean temperature changes, with the base period 1951-1980, for three latitude bands that cover 30%, 40% and 30% of the global area. Uncertainty bars (95% confidence limits) are based on spatial sampling analysis. [This is an update of Figure 5 in Hansen et al. (1999).]

Annual Mean Temperature Change in the United States

Annual and five-year running mean surface air temperature in the contiguous 48 United States (1.6% of the Earth's surface) relative to the 1951-1980 mean. [This is an update of Figure 6 in Hansen et al. (1999).]